PURPOSE: A laser irradiation method is provided to uniformly irradiate in the front side of a wafer by irradiating a pulse type laser beam having high frequency as distance from center of the wafer increases. CONSTITUTION: A circular wafer(150) is installed on a stage(100). The stage is installed to be possible to rotate. The wafer is rotated. A pulse type laser beam is irradiated in the front side of the wafer from a processing head(130) which is prepared to be possible to move. The processing head is formed to be possible to move from the center of the wafer to a radial direction of the wafer. Frequency of the pulse type laser beam is controlled by a q-switch which is included in an output end of the processing head. The q-switch comprises an EO(Electro-Optic) q-switch or an AO(Acoustic-Optic) q-switch.
申请公布号
KR20120016453(A)
申请公布日期
2012.02.24
申请号
KR20100078823
申请日期
2010.08.16
申请人
EO TECHNICS CO., LTD.
发明人
CHUNG, YOUNG DAE;SEONG, CHEON YA;KIM, HYUN GUK;LEE, KAM MYUNG;KIM, HWAN